Expression of the "helper component" protein of Potato Virus Y (PVY) in E. coli: possible involvement of a third protease

• Published in: Virus genes Vol. 7; no. 2; p. 151
• Main Authors: Stram, Y. (Hebrew Univ. of Jerusalem, Rehovot (Israel). Otto Warburg Center for Biotechnology), Chetsrony, A, Karchi, H, Karchi, M, Edelbaum, O, Vardi, E, Livneh, O, Sela, I
• Format: Journal Article
• Language: English
• Published: United States 01.06.1993
• Subjects: ADN; Cloning, Molecular; Cysteine Endopeptidases - genetics; DNA; DNA, Viral - genetics; Endopeptidases - genetics; ESCHERICHIA; Escherichia coli - genetics; EXPRESION GENICA; EXPRESSION DES GENES; GENE EXPRESSION; Plant Viruses - enzymology; Plant Viruses - genetics; POTATO VIRUS Y; PROTEASAS; PROTEASE; PROTEASES; Viral Proteins - genetics; VIRUS Y DE LA PAPA; VIRUS Y DE LA POMME DE TERRE
• ISSN: 0920-8569; 1572-994X
• DOI: 10.1007/BF01702395

Transmission of potyviruses by aphids depends on the presence of a virus encoded helper-component protein (HC) that also exhibits protease activity. HC was expressed in E. coli from two types of clones: a full-length cDNA clone of PVY and two 5' end clones containing the first three cistrons (3.6-3.7 kbp). The clones derived from the 5' end of PVY expressed HC of the size of the mature component. Other proteins reacting with antibodies to HC were also observed, and their sizes corresponded with those of expected intermediates resulting from partial protease cleavage of the three-cistron polyprotein. On the other hand, the only detectable HC-related product of the full-length clone was a mature-size HC. The presence of a third PVY protease among the first three cistrons is therefore suggested.